Crypto Archeology: Unearthing Design Methodologies of DES S-Boxes

2017 ◽  
Vol 2 (9) ◽  
pp. 30-34
Author(s):  
Sankhanil Dey ◽  
Ranjan Ghosh
Keyword(s):  
Boolean Functions ◽  
Design Methodology ◽  
Block Ciphers ◽  
Public Domain ◽  
Keen Interest ◽  
Design Methodologies ◽  
Substitution Boxes

US defense sponsored the DES program in 1971 and released it on 1977. It remained as a well-known and well-accepted de-facto standard of block ciphers until 1998. Thirty-two 4-bit DES S-Boxes are grouped in eight each having four and are put in public domain without any mention of their design methodology. Due to this discovery of substitution Boxes, S-Boxes, 4-bit, 8-bit or 32-bit, find a permanent seat in all future block ciphers. In this paper, a brief study on Crypto relevant properties of 4-bit Boolean Functions as well as 4-bit S-Boxes has been elaborated. The design Methodology of 32 4-bit DES S-Boxes have been of keen interest of this paper. The methodology of such 4-bit DES S-boxes that remained unturned due to the interference of NIST, have also been elaborated in this paper.

scholarly journals Crypto-Archaeology: unearthing design methodology of DES s-boxes

2017 ◽  
Author(s):  
Sankhanil Dey ◽  
Ranjan Ghosh
Keyword(s):  
Boolean Function ◽  
Boolean Functions ◽  
Design Methodology ◽  
Block Cipher ◽  
Block Ciphers ◽  
Public Domain ◽  
Differential Cryptanalysis ◽  
Linear Cryptanalysis ◽  
Strict Avalanche Criterion ◽  
Independence Criterion

US defence sponsored the DES program in 1974 and released it in 1977. It remained as a well-known and well accepted block cipher until 1998. Thirty-two 4-bit DES S-Boxes are grouped in eight each with four and are put in public domain without any mention of their design methodology. S-Boxes, 4-bit, 8-bit or 32-bit, find a permanent seat in all future block ciphers. In this paper, while looking into the design methodology of DES S-Boxes, we find that S-Boxes have 128 balanced and non-linear Boolean Functions, of which 102 used once, while 13 used twice and 92 of 102 satisfy the Boolean Function-level Strict Avalanche Criterion. All the S-Boxes satisfy the Bit Independence Criterion. Their Differential Cryptanalysis exhibits better results than the Linear Cryptanalysis. However, no S-Boxes satisfy the S-Box-level SAC analyses. It seems that the designer emphasized satisfaction of Boolean-Function-level SAC and S-Box-level BIC and DC, not the S-Box-level LC and SAC.

scholarly journals Crypto-Archaeology: unearthing design methodology of DES s-boxes

2017 ◽  
Author(s):  
Sankhanil Dey ◽  
Ranjan Ghosh
Keyword(s):  
Boolean Function ◽  
Boolean Functions ◽  
Design Methodology ◽  
Block Cipher ◽  
Block Ciphers ◽  
Public Domain ◽  
Differential Cryptanalysis ◽  
Linear Cryptanalysis ◽  
Strict Avalanche Criterion ◽  
Independence Criterion

US defence sponsored the DES program in 1974 and released it in 1977. It remained as a well-known and well accepted block cipher until 1998. Thirty-two 4-bit DES S-Boxes are grouped in eight each with four and are put in public domain without any mention of their design methodology. S-Boxes, 4-bit, 8-bit or 32-bit, find a permanent seat in all future block ciphers. In this paper, while looking into the design methodology of DES S-Boxes, we find that S-Boxes have 128 balanced and non-linear Boolean Functions, of which 102 used once, while 13 used twice and 92 of 102 satisfy the Boolean Function-level Strict Avalanche Criterion. All the S-Boxes satisfy the Bit Independence Criterion. Their Differential Cryptanalysis exhibits better results than the Linear Cryptanalysis. However, no S-Boxes satisfy the S-Box-level SAC analyses. It seems that the designer emphasized satisfaction of Boolean-Function-level SAC and S-Box-level BIC and DC, not the S-Box-level LC and SAC.

scholarly journals Hamming-Code Based Fault Detection Design Methodology for Block Ciphers

2020 ◽  
Author(s):  
F. E. Potestad-Ordonez ◽  
E. Tena-Sanchez ◽  
R. Chaves ◽  
M. Valencia-Barrero ◽  
A. J. Acosta-Jimenez ◽  
...  
Keyword(s):  
Fault Detection ◽  
Design Methodology ◽  
Block Ciphers ◽  
Hamming Code

scholarly journals More Low Differential Uniformity Permutations over F22k with k Odd

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yue Leng ◽  
Jinyang Chen ◽  
Tao Xie
Keyword(s):  
Block Ciphers ◽  
Algebraic Degree ◽  
Differential Uniformity ◽  
Numerical Examples ◽  
High Nonlinearity ◽  
Substitution Boxes ◽  
Theoretical Results

Permutations with low differential uniformity, high algebraic degree, and high nonlinearity over F22k can be used as the substitution boxes for many block ciphers. In this paper, several classes of low differential uniformity permutations are constructed based on the method of choosing two permutations over F22k to get the desired permutations. The resulted low differential uniformity permutations have high algebraic degrees and nonlinearities simultaneously, which provide more choices for the substitution boxes. Moreover, some numerical examples are provided to show the efficacy of the theoretical results.

Crashworthy structures for future vehicle architecture of autonomous pods and heavy quadricycles on public roads: A review

2019 ◽  
Vol 234 (1) ◽  
pp. 3-16
Author(s):  
Andrew Harrison ◽  
Jesper Christensen ◽  
Christophe Bastien ◽  
Stratis Kanarachos
Keyword(s):  
Nonlinear Optimization ◽  
Design Methodology ◽  
Significant Risk ◽  
Optimization Methods ◽  
Functionally Graded ◽  
Vehicle Architecture ◽  
Design Methodologies ◽  
Expensive Problems ◽  
Computationally Expensive ◽  
Nonlinear Optimization Methods

With the development and deployment of lightweight vehicles to the market, inclusive of autonomous pods, a review of advanced crashworthy structures and the design methodology has been conducted as it is thought that super-lightweight vehicles may pose significant risk to the occupants if they are involved in a crash. It is suggested that tests should include oblique and multiple velocity impacts to cater for the effects of assisted driving systems of future vehicles. A review of current crash structures and design methodologies revealed that the most recent research do not cater to multiple crash scenarios, nor a shorter crush allowance, therefore resulting in poor crashworthiness performance. In addition, the arbitrary seat positioning shown in autonomous pods’ concepts vastly increases the risk to occupants. Greater enhancements to passive crashworthiness are imperative. To this end, functionally graded vehicle structures should be designed as it has been found that these can provide optimized solutions. Research into nonlinear optimization methods for computationally expensive problems will become central to this.

Stability check of tapered steel beams in fire

2019 ◽  
Vol 10 (4) ◽  
pp. 373-398 ◽  
Author(s):  
Carlos Couto ◽  
Élio Maia ◽  
Paulo Vila Real ◽  
Nuno Lopes
Keyword(s):  
Design Methodology ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Numerical Models ◽  
Design Methods ◽  
Steel Beams ◽  
Content Type ◽  
Design Methodologies ◽  
Accurate Design ◽  
Improved Design

Purpose The purpose of this paper is to assess whether the adaptation to fire of current proposals/design methodologies at normal temperature is capable of producing accurate predictions of resistance for the out-of-plane stability of tapered beams. Design/methodology/approach The adaptation of these methodologies to fire has been done by accounting for the reduction in steel material properties with the temperature. Results were then compared to FEM calculations by performing GMNIA analyses to determine the ultimate strength of the numerical models and to ascertain the validity and accuracy of the adapted methodologies. Findings Although all methodologies produce safe results at normal temperatures, only the general method is recommended for the safety verification at elevated temperatures, although the data points were overly conservative. This investigation demonstrates the need of proper and accurate design methods for tapered beams at elevated temperatures, which should be the subject of future developments. Research limitations/implications The research in this paper is limited to the adaptation of existing room temperature design methods to fire. Therefore, possible assumptions made during the conception of the initial formulae, which may be valid exclusively for 20ºC, may have been disregarded. Originality/value For the time being, design methodologies for the safety check of tapered beams for the case of fire are inexistent. This paper investigates the adaptation of existing room temperature design to the fire situation by providing insights on their accuracy level, as well as on how to proceed. Finally, a safe design methodology for tapered beams in case of fire is provided until improved design methods are developed.

Teaching Creative Design by Integrating General Design Theory and the Pahl and Beitz Methodology

2010 ◽  
Author(s):  
Tetsuo Tomiyama ◽  
Paul Breedveld ◽  
Herbert Birkhofer
Keyword(s):  
The Netherlands ◽  
Medical Devices ◽  
Design Education ◽  
Design Theory ◽  
Design Methodology ◽  
Theoretical Explanation ◽  
Creative Design ◽  
General Design ◽  
Improve Design ◽  
Design Methodologies

The design methodology developed by Pahl and Beitz (P&B) is one of the most widely taught design methodologies. However, this methodology is not easy to correctly exercise for non-experienced designers such as students. At TU Darmstadt in Germany, a method was developed to make students to realize the background philosophy of P&B, to reduce misunderstanding and misuse of the method, and to help them to arrive at creative design. At TU Delft in the Netherlands, an experienced designer who works on designing mechanical medical devices developed a method to generate creative designs. Although independently developed, these two methods share some commonality and have a potential to improve design education towards creative design. This paper is an attempt to give a theoretical explanation why these two methods facilitate creative design based on General Design Theory.

scholarly journals 4, 8, 32, 64 bit Substitution Box generation using Irreducible or Reducible Polynomials over Galois Field GF(pq)

2017 ◽  
Author(s):  
Sankhanil Dey ◽  
Ranjan Ghosh
Keyword(s):  
Boolean Functions ◽  
Galois Field ◽  
Data Encryption ◽  
First Century ◽  
Additive Constant ◽  
Substitution Box ◽  
Data Encryption Standard ◽  
Substitution Boxes ◽  
Early Twenty ◽  
Encryption And Decryption

Substitution Box or S-Box had been generated using 4-bit Boolean Functions (BFs) for Encryption and Decryption Algorithm of Lucifer and Data Encryption Standard (DES) in late sixties and late seventies respectively. The S-Box of Advance Encryption Standard have also been generated using Irreducible Polynomials over Galois field GF(28) adding an additive constant in early twenty first century. In this paper Substitution Boxes have been generated from Irreducible or Reducible Polynomials over Galois field GF(pq). Binary Galois fields have been used to generate Substitution Boxes. Since the Galois Field Number or the Number generated from coefficients of a polynomial over a particular Binary Galois field (2q) is similar to log2q+1 bit BFs. So generation of log2q+1 bit S-Boxes is possible. Now if p = prime or non-prime number then generation of S-Boxes is possible using Galois field GF (pq ), where q = p-1.

scholarly journals A review of cryptographic properties of S-boxes with generation and analysis of crypto secure S-boxes.

2018 ◽  
Author(s):  
Sankhanil Dey ◽  
Ranjan Ghosh
Keyword(s):  
Detailed Analysis ◽  
Boolean Functions ◽  
Public Key Cryptography ◽  
Galois Field ◽  
Data Encryption ◽  
Public Key ◽  
Data Encryption Standard ◽  
Detailed Review ◽  
Substitution Boxes ◽  
Modern Cryptography

In modern as well as ancient ciphers of public key cryptography, substitution boxes find a permanent seat. Generation and cryptanalysis of 4-bit as well as 8-bit crypto S-boxes is of utmost importance in modern cryptography. In this paper, a detailed review of cryptographic properties of S-boxes has been illustrated. The generation of crypto S-boxes with 4-bit as well as 8-bit Boolean functions (BFs) and Polynomials over Galois field GF(p q ) has also been of keen interest of this paper. The detailed analysis and comparisonof generated 4-bit and 8-bit S-boxes with 4-bit as well as 8-bit S-boxes of Data Encryption Standard (DES) and Advance Encryption Standard (AES) respectively, has incorporated with example. Detailed analysis of generated S-boxes claims a better result than DES and AES in view of security of crypto S-boxes.

Setting our bibliographic references free: towards open citation data

2015 ◽  
Vol 71 (2) ◽  
pp. 253-277 ◽  
Author(s):  
Silvio Peroni ◽  
Alexander Dutton ◽  
Tanya Gray ◽  
David Shotton
Keyword(s):  
Open Access ◽  
Linked Data ◽  
Design Methodology ◽  
Reference Lists ◽  
Public Domain ◽  
Citation Data ◽  
Pubmed Central ◽  
Content Type ◽  
Creative Commons ◽  
The Commons

Purpose – Citation data needs to be recognised as a part of the Commons – those works that are freely and legally available for sharing – and placed in an open repository. The paper aims to discuss this issue. Design/methodology/approach – The Open Citation Corpus is a new open repository of scholarly citation data, made available under a Creative Commons CC0 1.0 public domain dedication and encoded as Open Linked Data using the SPAR Ontologies. Findings – The Open Citation Corpus presently provides open access (OA) to reference lists from 204,637 articles from the OA Subset of PubMed Central, containing 6,325,178 individual references to 3,373,961 unique papers. Originality/value – Scholars, publishers and institutions may freely build upon, enhance and reuse the open citation data for any purpose, without restriction under copyright or database law.

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